Gusta-v unger



(No Model.)

G.UNGBR PURNAGE FOR BURNINGGOAL DUST.

No. 577,995. l Patented Mar. 2, 1897'.

UNITED STATES PATENT OFFICE.

GUSTAV UNGER, OF MAGDEBURG, GERMANY.

FURNAC FOR BURNING COAL-DUST.

SPECIFICATION forming part of Letters Patent No. 577,995, dated March 2, 1897'.

Application led August 29, 1896I Serial No. 604,830. (No model.) Patented in Switzerland July 22, 1895, No.10,714; in England July 2,4, 1895, No. 14,132,I in France July 24,1895,No.249,148; in Belgium July 29, 1895, No. 116,738, and in Austria November 26, 1895, No. ll5/4,475.

T0 all whom it may concern:

Be it known that l, GUsTAv UNGER, a subject of the King of Prussia, Emperor of Germany, residing at Magdeburg, in the Empire of Germany, have invented certain new and useful Improvements in Boiler and Like Furnaces for Burning Coal-Dust, (for which I have obtained Letters Patent in Austria, No. Ll5/4,475, dated November 26, 1895; in Belgium, No. 116,738, dated July 29, 1895; in France, No. 249,148, dated July 24, 1895 -in Switzerland, No. 10,714, dated July 22, 1895, and in England, No. 14,132, dated July 24, 1895,) of which the following is a specilication.

This invention relates to improvements in boiler and like furnaces for burning coal-dust or disintegrated fuel and in self-acting stokers therefor.

Heretofore furnaces for burning coal-dust have been defective by reason of their being built exclusively of a fireproof grateless chamber, whereby at the beginning of as well as during the working gases or even flames pass suddenly through the air-feed holes of the nre-chamber toward the outside, and these flames or gases carry away with them more or less unburned coal-dust or fuel. The cause of these eruptions, which take place under conditions similar to explosions, is due to the fact that the temperature of thewalls of the fire-chamber changes continuously, and it can be observed through inspection-holes that the said walls are sometimes bright red, sometimes incandescent or glowing, and at other times dull red. This defect is, in the construction which forms the object of this invention, obviated by removing on the one hand the front part of the base of the lire-chamber and substituting therefor an ordinary grate, (plane grate, inclined grate, or stepped grate,) and on the other hand by causing the coaldust or powdered or disintegrated fuel to fall from above directly into the nre-chamber in the form of a veil or cloud extending over the whole width of the lire-chamber.

For starting the re ordinary fuel is ignited upon the grate. As soon as the fire-chamber then appears sufciently hot the disintegrated fuel-'for instance, coal-dust-is fed therein. Above the iiame which starts from the grate another iame will be observed to pass along below the crown of the fire-chamber. This second flame is generated by the particles of 'coal' which,by the action of the chimney-draft,

are drifted along below the crown of the firechamber. Those particles of coal or other fuel which fall down toward the front and up to about the middle of the chamber will come within the reach of the flame which rises from the grate, and these particles are partly carried forward by the said flame and partly fall through the flame upon the lire of the grate and are burned there. Both of the said flames join and penetrate each other immediately behind the grate and ignite all particles of coal or other fuel existing in and between the same and consume the whole of the smoke still present there. In this manner a complete combustion is obtained.

When regularly worked, the disintegrated fuel falls upon the grate, so that the fire need not or only seldom be rearranged.

In the accompanying drawings a constructional form of this improved ring arrangement is illustrated. As an example a Lancashire boiler has been chosen.

Inl the said drawings, Figure l is a longitudinal section of the boiler and furnace; and Fig. 2 is a front view of the boiler, one of the furnaces being shown in section.

The fire-chamber a, made of reproof material, projects from the furnace-tube b. The base of this projecting portion is formed by an ordinary grate c, below which is arranged an ash-pit provided with a liap-door cl, and above whichan ordinaryfire-door g is provided inthe front wall f of the fire-chamber. Between the front grate-carrier and the firedoor a slit h is left, which can be closedby means of a slide or damper 'l'. Above the front extremity of the grate lies the mouth of the feed-channel le, traversing the top cover of the lire-chamber. This feed-channel serves for introducing the coal-dust or other fuel and extends over the whole width or nearly the whole width of the nre-chamber, as is shown in dotted lines in Fig. 2. The said channel can be more or less or entirely closed by means of a flap or door Z. Below the place where the feed-channel 7o has its outlet-orice into the fire-chamber a a transverse slit m passes through the front wall f of the charnber, (see also Fig. 2, left hand,) which slit can likewise be closed by means of a slide or damper n.

For feeding the coal-dust or the like various arrangements may be employed. The device which is shown as an example is arranged in the following manner: The top or cover of the lire-chamber carries above the feed-channel 7c a box-shaped receptacle o, the cover or lid of which is provided with a tubular feed-socket, which communicates through a leather hose or pipe with a feed-channel q. In the box o a second receptacle r is movably suspended from one or several pins or pivots or by other suitable means. The bottom of the receptacle r has a tapering portion t, in which a lateral slit a is left, which can be narrowed by means of a slide r. The lowermost edge of the movably-suspended receptacle presents itself slightly above a feedroller w, provided with suitable longitudinal grooves, which roller, like the receptacle r, extends over the whole width of the firechamber. This roller, which instead of being provided with grooves may also be simply roughened at its surface-for instance, like an undressed cast metal cylinder-is driven from outside. The roller has several projections e, arranged at equal distances apart, which, when the roller is rotated, will set the receptacle r in a rocking motion and thereby cause the whole contents of the receptacle up to its uppermost layers to slip down gradually. Thus coal-dust or like disintegrated fuel drops out of the receptacle 'r through the slit u upon the periphery of the roller, the rotary speed of which-amountin g to about twenty revolutions per minute-also permits of the actuation by hand and is dependent upon the quality of the fuel used. In order that the roller may not carry away too much of the disintegrated fuel, a sheetplate 0c, acting as a scraper, is movably suspended above the roller in front of the slit u, which scraper-plate is, by means of counterweight y, 'always forced back into its initial or resting position, and which, moreover, has the obvious advantage of overcoming without obstruction any irregularities in the action caused by a comparatively coarse sort of fuel and other admixtures, the action being such that the scraper-plate simply rises, thus allowing of the coarser particles of fuel being forced into the nre-chamber by the energetic and steady action of the roller. During its rotary motion the roller spreads the powdered fuel resting thereon down in the feedchannel k with such a speed that the fuel passes the said channel 7c in form of a veil or cloud and also enters the fire-chamber in this form.

In case where the fuel is moist or wet further scraping devices of any suitable kind may be arranged at the place where the material leaves the roller.

Before the fuel-feeding device is set in movement the fire-chamber must be first heated by arranging and keeping a iire upon the ordinary grate c. This having been done, the fuel is fed down, and then the before-described proeess will take place. Owing to the fact that the fuel freely falls down in the shape of a thin veil or cloud, the said fuel is intimately mixed with air, whereby one principal condition for securing a complete combustion is fulfilled. On the other hand, the cooling down of the walls of the {ire-chamber, which under other conditions occurs frequently, is prevented, owing to the fact that the fire on the grate will always give oif a uniform heat.

Owing to the absolute combustion of all particles of fuel introduced obtained in this manner, the explosions hereinbefore mentioned are entirely avoided.

Through inspection-holes arranged in the front wall of the chamber it can be ascertained whether the combustion takes place in a regular manner. If it is observed that for obtaining a complete combustion a larger amount of air is required than enters at the bottom through the slits between the grate and from above, together with the disintegrated fuel through the feed-channel 7c, one opens the slit h in front of the grate and the slit m in the front wall of the fire-chamber to a greater or less extent accordingly. On further observing that the Veil or cloud of coal-dust or other fuel supplied is too thick for being completely burned, the feed passage or slit u of the recept-acle 7l is narrowed. Finally by adjusting the Hap Zin the feedchannel 7c it is given in ones command to more or less deviate the veil or cloud of coaldust-that is to say, to impart to it the most suitable direction for the purpose.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. In a furnace for burning powdered or disintegrated fuel the combination of an ordinary grate forming the front part of the base of the fire-chamber, and of a feed-channel being situated above the said grate, traversing the top cover of the fire-chamber and extending over the whole width or nearly the whole width of the fire-chamber, with a fuelfeed device comprising a feed-roller roughened or provided with appropriate recesses and a fuel-receptacle set in rocking motion by the said roller, substantially as described.

2. In a furnace for burning powdered or disintegrated fuel the combination of an or- ICO IOS

IIO

1o said roller, and et scraping device or devices actin g upon the said feed-roller, substantially as described. A

In testimony whereof I lhave signed my name to this specication in the presence of tWo subscribing Witnesses.

GUSTAV UNGER.

Witnesses:

AUGUST MUHLE, A. VoGT. 

